Farrow made her professional stage debut as Cicely in a 1963 Off-Broadway of Oscar Wilde's comedy of manners "The Importance of Being Earnest". Employing a letter perfect English accent, the actress garnered attention, partly through the influence of family friend Vivien Leigh who encouraged casting agents and journalists to see the production. Producer Paul Monash attended one performance and went backstage to ask Farrow if she was capable of doing an American accent as he wanted her to star in a primetime TV show. For her part, she preferred to remain in NYC and pursue a stage career, but she agreed to test for the role of Alison MacKenzie for ABC's groundbreaking primetime serial adaptation of "Peyton Place". Before she landed that role which would confer "overnight star" status, Farrow lucked into her first major film role, replacing another actress as the Swedish United Nations secretary in "Guns at Batasi" (1964).

Convinced that no one would watch "Peyton Place", which was scheduled to air three times a week, Farrow began looking for other work. To her surprise, the show not only became a hit but she was one of the performer singled out. She was now a "star". After two years (1964-66), though, Farrow had had enough and sought release from her contract. By that point she harbored a desire to work in other projects (like the 1967 small screen remake of "Johnny Belinda"). In addition, she had become engaged to singer-actor Frank Sinatra. After what seemed like a whirlwind courtship, they married but the strain of a two career household made it short-lived. Farrow was in demand as a young leading lady and by the time of her divorce from Sinatra was headlining two films, "A Dandy in Aspic" and the now classic thriller "Rosemary's Baby" (both 1968).

For "Rosemary's Baby", she had cut her long hair and projected a waiflike persona as the newlywed who discovers that her husband and her neighbors are Satanists. Farrow earned raves for her performance (Pauline Kael deemed her "just about perfect") and there was buzz about an Oscar nomination but that did not pan out. She followed with another fragile young woman alongside Elizabeth Taylor in "Secret Ceremony" (also 1968) and her success at portraying these child-women threatened to typecast her. Farrow continued to seek challenging roles (a blind woman stalked by a killer in the chilling "See No Evil" 1971) but after the birth of twins and her subsequent marriage to composer-conductor Andre Previn in 1970, she curtailed her activities. In 1974, Farrow was cast as the Southern belle Daisy Buchanan in the lavish remake "The Great Gatsby", but she seemed miscast when the film was finally spooled in theaters. Additionally, there was virtually no romantic chemistry with lead Robert Redford diluting the basic arc of the story. On the other hand, Farrow was delightful as "Peter Pan" in an NBC "Hallmark Hall of Fame" production although she could not erase the indelible memory of Mary Martin in the role.

Motherhood became a top priority until her separation from Previn. In 1978, she offered intriguing if not always successful performances like her mute bridesmaid in Robert Altman's "A Wedding" and her jilted lover in the all-star Agatha Christie adaptation "Death on the Nile". After a misguided turn in "The Hurricane" (1979), she began an association that had ramifications on her professional and personal life. She had been introduced to filmmaker Woody Allen by Michael Caine and in 1982 assumed the role of his muse. Beginning with the lightweight "A Midsummer Night's Sex Comedy" (1982) and stretching to "Husbands and Wives" (1992), Farrow got to create an astonish array of characters. Her best work under Allen's guidance included the 1920s psychiatrist in "Zelig" (1983), the brassy gangster's moll in "Broadway Danny Rose" (1984), the downtrodden wife in "The Purple Rose of Cairo" (1985) and the luminous center of "Hannah and Her Sisters" (1986, which was filmed in large part in her Central Park West apartment). The underrated "Alice" (1990), a spin on Lewis Carroll's tale, offered her another strong role, but it was around this time that her personal life began to unravel. As she was later to discover, Allen had begun a relationship with one her adopted daughters (Soon-Yi Previn whom he later married). When she discovered the affair, it unfortunately became fodder for the tabloids, partly as Farrow accused Allen of molesting their adopted daughter. The messy situation played out in the courts (with Allen denied custody of the two children he adopted with Farrow as well as their biological child) and Farrow retreated to tend to her family.

Eventually, she returned to work in the comedy "Widow's Peak" (1994), in which she once again used her seemingly fragile persona as a shield for secret resources. She delivered a virtuoso performance as the heroine of "Reckless" (1995), adapted from Craig Lucas' play. As the 90s wound down, Farrow returned to the small screen to play a Danish woman aiding Jews during WWII in "Miracle at Midnight" (ABC, 1998) and a young victim of Alzheimer's disease in "Forget Me Never" (CBS, 1999).